At present, the power machines used in the world are mostly external combustion engines, internal combustion engines and electric motors. The external combustion engine mainly refers to steam engine which, as a symbol of the industrial revolution in the eighteenth-century, has promoted the advancement of the modern industrial society. However, the steam engine has some disadvantages. It cannot be separated from the boiler which makes the whole device very large and bulky. The pressure and temperature of new steam cannot be too high, and the discharge pressure cannot be too low, so the thermal efficiency can hardly be increased. It is a reciprocating machine that the inertial force limits the speed of rotation. In addition, its working process is discontinuous, and the flow of the steam is limited, which in turn limits the increase of the power.
In a general sense, the internal combustion engine includes not only a reciprocating piston internal combustion engine, a rotary vane gas turbine and a free piston engine, but also a rotary vane gas turbine and a jet engine. Usually, an internal combustion engine refers to a piston internal combustion engine.
The internal combustion engine, which has abandoned the bulky boiler, has gradually replaced the steam engine in the ship or in the locomotive, due to its advantages of light weight, small size, high thermal efficiency and flexible operation.
Since its introduction in the 1860s, the piston internal combustion engine has become a comparative perfect machine after the unceasing improvement and the development. The piston internal combustion engine has been widely used for its features of high thermal efficiency, wide power and range of rotation speed, convenient supporting and good mobility. Around the world, various types of machines, such as automobile, tractor, farm machine, engineering machine, small mobile power station and chariot, are powered by an internal combustion engine. Merchant ships on a sea or on a river, conventional warships and some small planes are also propelled by the internal combustion engine. The amount of the internal combustion engines is above all other power machines in the world, and the internal combustion engine plays a very important role in human activities.
Compared with the piston internal combustion engine and the steam powered device, the main advantages of the gas turbine are small and light. The weight per unit power of the heavy-duty gas turbine is generally 2-5 kilograms per kilowatt, and the weight per unit power of the airplane is below 0.2 kilogram per kilowatt. The gas turbine occupies a small area, and when it is used in a transport machine, such as a vehicle or ship, it can save space, or a gas turbine of larger power can be provided to improve the speed of the vehicle or ship. The main disadvantage of the gas turbine is its low efficiency that its efficiency decreases quickly under part-load condition and the fuel consumption is high under non-load condition.
Then the electric motor, with its convenience, replaces the steam engine in the industry equipment.
The piston internal combustion engine has the advantages of high heating efficiency, small size and large application range. The gas turbine has the advantages of small size, light weight and high single-machine power, which can save space; a gas turbine of larger power can be equipped to improve the speed of the vehicle or ship. However, the oil energy consumed by the internal combustion engine is non-renewable energy. After more than a hundred years' development and industrialized application, the oil energy is becoming drained, and the energy crisis is closely approaching. To leave our future generations remaining valuable resources, energy saving, emission reduction, searching and developing a reproducible energy are becoming important and urgent for us.
Carbon dioxide and other waste gases generated and discharged by the internal combustion engine are major contributors to global greenhouse effect, which make global environmental issues become more and more serious. Therefore, both of energy security and environmental issue become obstacles for the further development of the internal combustion engine.
The electric motor is now an ideal power machine in the energy field and in environmental protection, which has a small size and wide range of application. However, compared with the internal combustion engine, the electric motor has outstanding problems of low power and small torque, and in the case of high power, the electric motor has problems of high calorific value and high power consumption. These problems thus limit the development and application of the electric motor in many fields.
The subject and objective of the present invention are to study and invent a power machine which use clean energy sources and is energy-efficient.